Affiliated Managers Group Inc. (NYSE: AMG) has made an additional investment in AQR Capital Management LLC.

AQR, headquartered in Greenwich, Connecticut, is an investment manager with about $115 billion in assets under management. The company also has offices in Chicago, London, Sydney and Bermuda. Terms of the deal were not disclosed. Affiliated Managers picked up a minority stake in AQR in 2004.

Affiliated Managers continues to hold a minority interest in the firm. The buyer is an asset management company that makes equity investments in boutique investment management firms. As of Sept. 30, the group had about  $617 billion in assets under management, including those of affiliates.

In March, Affiliated Managers agreed to buy U.S. equities manager River Road Asset Management LLC from Aviva Investments. 

Other recent asset management acquisitions have come from Victory Capital, which picked up Compass Efficient Model Portfolios LLC in December, and Securian Financial Group, which bought a majority stake in Asset Allocation & Management Co. in November. 

M&A in the sector is expected to continue, according to Mergers & Acquisitions’ Mid-Market Pulse (MMP), a forward-looking sentiment indicator derived from monthly surveys of approximately 250 executives. For more, see Deal Professionals Predict Financial Services M&A Will Soar. For more on financial services, see Financial Services Sector Will Continue to Consolidate.